Endoscope Illumination Optical System Near-Field Halation Control
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Solution Overview
Problem
Endoscope apparatuses face challenges in achieving uniform illumination and minimizing halation across varying observation distances due to the inefficient disposition of illumination optical systems, which affects brightness and light distribution.
Innovation Solution
The endoscope apparatus incorporates a plurality of illumination optical systems with different light-distribution characteristics, where the wide-angle illumination optical system is positioned closer to the observation optical system than the narrow-angle illumination optical system, allowing for optimal illumination based on near or far-field requirements, and satisfying specific conditional expressions to ensure uniform brightness and reduced halation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If multiple illumination optical systems are disposed to flank the observation optical system to efficiently irradiate a wide viewing field, then the illumination coverage is improved, but the distance arrangement between illumination systems and observation system becomes suboptimal for near-field observation
Solution Approach 1:
The illumination system is segmented into multiple illumination optical systems (first and second illumination optical systems) with different light distribution characteristics. Each system is positioned at different distances from the observation optical system, allowing optimized illumination for both wide-field and near-field observation without compromising either function
Solution Approach 2:
Different regions of the illumination system are assigned different light distribution properties. The first illumination optical system provides wide-angle illumination for general viewing fields, while the second illumination optical system provides concentrated illumination for near-field observation. This local differentiation of illumination quality resolves the contradiction between wide coverage and near-field performance
2Device complexity
If a single illumination optical system is used for both normal and near-field observation, then the device complexity is reduced, but the illumination uniformity and brightness become insufficient for varying observation distances
Solution Approach 1:
The illumination system is made dynamically adaptable to different observation conditions by incorporating multiple illumination optical systems with different light distribution characteristics. The system can selectively utilize appropriate illumination sources based on whether normal or near-field observation is being performed, enabling dynamic optimization of illumination quality without excessive complexity
3Stability of the object's composition
If the widest-angle illumination optical system is positioned farther from the observation optical system, then the light distribution uniformity improves, but the halation effect increases and near-field illumination brightness decreases
Solution Approach 1:
Different spatial positions in the illumination system are assigned different functional characteristics. The widest-angle illumination optical system is positioned closer to the observation optical system to provide uniform wide-field illumination, while the narrowest-angle system is positioned farther away to provide concentrated illumination without excessive halation. This local functional differentiation resolves the contradiction between uniformity and halation control
Data Source
AI summary
In order to perform a superior observation, in which halation is less likely to occur, by achieving uniform illumination from near sites to far sites and by ensuring a satisfactory light distribution and brightness, both when performing normal observation and when performing near-field observation, an endoscope apparatus includes an observation optical system that is provided at a distal end of an inserted portion of the endoscope apparatus to observe an observation subject and a plurality of illumination optical systems that are provided in the inserted portion and that illuminate the same viewing field by distributing illumination light emitted from a light source over the observation subject, wherein, of the plurality of the illumination optical systems, the distance from the observation optical system to the widest-angle illumination optical system is smaller than the distance from the observation optical system to the narrowest-angle illumination optical system.